What is the ohm symbol?

The ohm symbol is Ω, the uppercase form of the Greek letter omega. It represents the ohm, the SI unit of electrical resistance, named after physicist Georg Ohm.

How do I type the ohm symbol on a keyboard?

On Windows, hold Alt and type 234 on the numeric keypad. On Mac, press Option+Z. You can also copy it directly from this page.

Is there a difference between Ω (omega) and the ohm sign?

Unicode defines both: U+03A9 GREEK CAPITAL LETTER OMEGA and U+2126 OHM SIGN. The OHM SIGN is a legacy compatibility character that normalizes to omega, so most fonts render them identically. Using the Greek omega (U+03A9) is recommended for new text.

What is the LaTeX command for the ohm symbol?

In math mode, use \Omega, which renders as Ω. Some packages also provide \ohm for a upright, non-italic version suited to units.

How do I write kilo-ohms and mega-ohms?

Kilo-ohms are written kΩ (1,000 ohms) and mega-ohms are written MΩ (1,000,000 ohms). Both use the same Ω symbol with an SI prefix.

Ohm Symbol

Name: Ohm Symbol
Availability: InStock
Author: Nham Vu

Click the ohm symbol (Ω) to copy it, or copy its Unicode, LaTeX, and HTML entity codes.

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Greek capital letter omega (U+03A9)

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Codes & Formats

Unicode code point

U+03A9

HTML entity (named)

HTML entity (numeric)

CSS / JS escape

\03A9

LaTeX command

\Omega

Windows Alt code

Alt + 234

Mac shortcut

Option + Z

Resistor Notation Examples

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Summary

Click the ohm symbol (Ω) to copy it, or copy its Unicode, LaTeX, and HTML entity codes.

How it works

Click the large Ω symbol to copy it to your clipboard.
Pick a code format (Unicode, HTML, LaTeX, Alt code) and click its copy button.
Use the resistor notation examples for common values such as 4.7kΩ or 1MΩ.
Paste the copied symbol or code into your document, spreadsheet, or code editor.

Use cases

Insert the ohm symbol into a circuit diagram label or datasheet.
Write resistor values like 220Ω, 4.7kΩ, or 1MΩ in a bill of materials.
Add the Unicode or HTML entity code to a web page or LaTeX document.
Type the ohm symbol on a device where the Greek omega key is not available.
Reference the difference between the Greek letter omega and the dedicated ohm sign character.

Frequently Asked Questions

Last updated: 2026-07-22 · Reviewed by Nham Vu